Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 111955

255 PM CDT Thu Sep 11 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 252 PM CDT Thu Sep 11 2014

Clouds have not cleared out this afternoon even though high
pressure has begun to build into the low levels. This is because
of persistent low level inversion that the RAP is showing around
900mb. Moisture is being trapped below this inversion, so expect
these clouds to persist into the night. Drizzle may redevelop over
the area toward morning. Temperatures did not climb much today and
do not have far to fall tonight to reach agreeable MOS guidance
for lows.


.LONG TERM:  (Friday through Next Thursday)
Issued at 252 PM CDT Thu Sep 11 2014

Next shortwave to continue sliding southeast into forecast area on
Friday. Models in good agreement on timing and precipitation
associated with it. Will see isolated/widely scattered showers
develop and spread southeast across forecast area during the day
on Friday exiting late Friday evening. QPF amounts will be rather
light with best chances along and north of I-70. As for
temperatures, to remain well below normal with highs only in the
upper 50s to upper 60s. Lows Friday night will be in the low 40s
to low 50s.

Then on Saturday, strong ridge of high pressure to build in and
skies to clear out. Despite the sunshine, it will continue to feel
like fall with high temperatures only in the 60s and lows Saturday
night in the 40s.

By Sunday, surface ridge begins to move off to the east allowing
temperatures to slowly moderate. Highs will be in the upper 60s to
low 70s. Then Sunday night the next weather system to approach the
region with showers developing and spread southeast through region
Sunday night through Monday night. Frontal boundary to stall out
just south of forecast area early Tuesday morning with weak surface
ridging building in. Could see some lingering isolated/scattered
showers through Wednesday night for western and southern portions of
the area. As for temperatures, highs will be in the 70s and lows in
the 50s through next Thursday.


.AVIATION:  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1226 PM CDT Thu Sep 11 2014

Expect mainly MVFR conditions to persist through the rest of the
TAF period. Current ceilings are expected to improve to above 2000
feet this afternoon, though the are expected to remain below 3000
feet through the night. Ceilings are expected to fall below 2000
feet with some IFR conditions possible between 08-16Z as drizzle
redevelops at the terminals. Conditions will then improve again by
mid morning Friday. Winds will be north to northeast and and
remain under 10kts.

Specifics for KSTL: Expect MVFR ceilings to persist through the
period, with bases increasing above 2000ft this afternoon.
Ceilings will fall back below 2000ft between 09-15Z with -dz
redeveloping at the terminal. Improvement is then expected after
mid morning Friday.



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